Survival of American black ducks radiomarked in Quebec, Nova Scotia, and Vermont
Article Abstract:
There is a need for an improved harvest strategy for American black ducks in North America to permit growth in breeding populations. This research, undertaken in Les Escoumins, Quebec, and Kamouraska, Quebec, Amherst Point, Nova Scotia, and a site on the Vermont-Quebec border, sought to test the null hypothesis that survival of radiomarked black ducks did not vary among four locations with different harvest regulations and hunter numbers. Survival appeared related to season length, but that effect was influenced by location, which was also connected with season length. A more conservative harvest policy should be introduced in regions of greatest harvest.
Publication Name: The Journal of Wildlife Management
Subject: Zoology and wildlife conservation
ISSN: 0022-541X
Year: 2000
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Outcome of aggressive interactions between American black ducks and mallards during the breeding season
Article Abstract:
Declining numbers of the American black duck concern waterfowl managers and it has been suggested that hybridization between black ducks and the more populous mallards, together with competitive exclusion from breeding grounds, may account for the decrease. A study of the competitive exclusion theory is designed to record the outcome of aggressive interactions and to determine if mallards displace black ducks on wetlands. The study of ducks in northeastern Maine shows that there is no link between declines in black duck populations and mallard duck increases, with wetland displacement being rare. It is suggested that hunting mortality is a more likely explanation.
Publication Name: The Journal of Wildlife Management
Subject: Zoology and wildlife conservation
ISSN: 0022-541X
Year: 1998
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Brood sizes of sympatric American black ducks and mallards in Maine
Article Abstract:
The long-term decrease in populations of the American black duck could be linked to the lower productivity of black ducks ousted from their wetland breeding sites by mallards, but there is little field data to support this hypothesis. A study of wetland areas in Maine during 1993 and 1994 shows no differences in the brood size of black ducks and mallards and suggests that competition from mallards is not reducing black duck productivity.
Publication Name: The Journal of Wildlife Management
Subject: Zoology and wildlife conservation
ISSN: 0022-541X
Year: 1998
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